1. Field of the Invention
The present invention relates to door locks, and, more particularly, to a lock assembly having a fire resistant spindle linkage.
2. Description of the Related Art
Some doors and associated lock assemblies, such as those used in commercial buildings, are designed to aid in protecting against the spread of fire by preventing the passage of fire from one room to another. In order to do so, a lock assembly may be designed to ensure that the associated door is maintained in a closed and latched state in the event of fire. In some such lock assemblies, pivot joints in the latch actuation linkage may be designed with internal fusible links which may be melted at fire temperatures to render the latch actuation linkage nonfunctional, and thus the door remains latched. In some situations, however, one or more passageways through the lock mechanism may be open, or become opened as a result of the fire, which potentially may not adequately inhibit the spread of fire.
What is needed in the art is a lock assembly having a fire resistant spindle linkage. The present invention provides such a solution.